Alexa - where is Amazon opening a new R&D centre? Cambridge, England

The Amazon Echo, a voice-controlled virtual assistant, is seen at its product launch for Britain and Germany in London, Britain, September 14, 2016. REUTER/Peter Hobson

LONDON (Reuters) - Amazon plans to open a new centre in the university city of Cambridge for scientists developing technologies including the Alexa digital assistant used in its Echo speakers.

Able to house more than 400 scientists and engineers when it opens in the autumn, the building underscores the U.S group's commitment to Britain, where Amazon said it has invested 6.4 billion pounds since 2010.

Amazon's existing centre in the city in the east of England, which sits at the heart of a regional technology hub known as "Silicon Fen", will be used to develop Prime Air, its programme to use drones to deliver parcels to customers in 30 minutes or less after the new building opens, Amazon said on Thursday.

Like fellow U.S. tech giants Google, Apple and Facebook, Amazon has continued to invest in Britain despite last year's vote to leave the European Union.

It has pledged to create 5,000 new roles across the country this year, bringing its workforce to 24,000.

"By the end of this year, we will have more than 1,500 innovation related roles here in Britain, working on everything from machine learning and drone technology to streaming video technology and Amazon Web Services," Doug Gurr, UK country manager for Amazon, said.